1. Technical Field
The present invention relates to an electronic cash system, and more particularly to an electronic cash system for processing a payment for an amount due with previously deposited funds.
2. Background Art
Current cash management schemes for electronic cash systems may be generally classified into a “balance management scheme” which manages the balance, utilizing devices immune to tampering, on the assumption that the balance cannot be tampered, and an “electronic bank note scheme” which assigns a face value and an identification number to electronic cash in order to manage the ID of cash issued by a center to check whether or not any bank note is double spent.
To put an electronic cash system to a practical use, it is necessary to realize the anonymity for user's personal information and purchase information, and an open loop type distribution which enables money to be transferred among arbitrary user devices, shops, and so on.
Mondex (trade name) is an electronic money system in accordance with the balance management scheme which satisfies the requirements mentioned above and has been widely used. In Mondex, serviced user devices and shops offering articles each hold a Mondex card, and the shops are further required to be equipped with a special apparatus for reading from and writing into a Mondex card, so that electronic cash is inputted or outputted therethrough.
The security on the user of Mondex on the Internet relies on the security ensured by the Mondex card which enhances the security by always providing two cryptographic modules such that the card is utilized by switching one of the modules which ensures the security. Also, since the Mondex system does not manage trade information at all, the anonymity is held for personal information and purchase logs.
With the Mondex system, however, the shops are required to manage special apparatus and burdened with labor and time therefor. In addition, since the Mondex system does not manage any trade information, an unauthorized use, if any, cannot be detected. Furthermore, the circulation of money cannot be managed.